Jet fuel additive

ABSTRACT

A method of reducing manganese containing deposits formed on the surfaces of jet engines from burning fuel containing organomanganese compounds as a smoke reducer is described. The deposits are reduced by adding an organic molybdenum compound to the organomanganese containing fuel. Cyclopentadienyl manganese tricarbonyl compounds are useful organomanganese compounds; molybdenum naphthenate is a useful molybdenum compound.

mted States Patent m1 0 1 3,718,444

Hnizda [451 Feb. 27, 1973 [5 1 JET FUEL ADDITIVE 3,153,901 10/1964 R100..44/68 3,402,188 9 1968 W' ...44 68 [751 Invenm" F Hmzd! 3,446,7355i1969 .;...44i6s Woods, Mich. 73 Assignee: Ethyl CorporationQNew'York,NY. Primary Examiner-139M915 y 1 Assistant Examiner-Mrs. Y. H. Smit [22]Ffled: 1968 AttorneyD0na1d L. Johnson [21] Appl. No.: 785,800

- [57] ABSTRACT 52 us. (:1 ..44/66, 44/68 A method of reducing manganesecontaining deposits 51 1111.01. ..C10l1/26 form on the Surfaces of jetengines from burning 58 Field at Search ..44/57, 66, 68 fuel containingorganomaflgamese as a smoke reducer is described. The deposits arereduced [56] References Cited by adding an organic molybdenum compoundto the organomanganese containing fuel.

. UNITED STATES PATENTS Cyclopentadienyl manganese tricarbonyl compounds2,737,932 3/1956 Thomas ..44/68 UX are useful organomanganese compounds;molyb- 2,88l,062 4/1959 Bisho ..44/68 denum naphthenate is a usefulmolybdenum com- 3,003,ss9 10/1961 Irish etal ..44/68 pound 3,109,01010/1963 Wilkinson ..44/68 3,112,789 Percy et al.... ..44/68 14 Claims,No Drawings JET FUEL ADDITIVE BACKGROUND OF THE INVENTION of usefulcompounds of this type, and includes methods of preparing them. Althoughuse of these manganese additives substantially reduces the exhaustsmoke, a secondary problem may arise in some instances. On

combustion of the fuel containing the manganese compound, manganesecontaining deposits are formed on the engine surface which was contactedby the exhaust products. As with many engine deposits, an effectivemethod of reducing these manganese containing deposits is desirable.

SUMMARY OF THE INVENTION A method of reducing manganese containingdeposits formed on the surfaces of jet engines which burn fuelcontaining organomanganese compounds, which comprises adding to saidfuel prior to burning, a deposit reducing amount of an organicmolybdenum compound; jet fuels containing an organomanganese compoundand a deposit reducing amount of an organic molybdenum compound.

DESCRIPTION OF PREFERRED EMBODIMENT An embodiment of this invention is amethod of reducing manganese containing deposits formed on the surfaceof a jet engine from burning a fuel containing a smoke reducing quantityof a cyclopentadienyl manganese tricarbonyl, wherein thecyclopentadienyl radical has up to 17 carbon atoms; which comprisesadding to said fuel prior to burning, a deposit reducing amount of asuitable molybdenum compound. 'A preferred embodiment involves use as adeposit reducer of an organic molybdenum compound selected from thegroup consisting of 1. molybdenum chelates and 2. molybdenum'salts of Ia. phenol and c,-c,, alkyl substitutedphenols b. phosphoricacids havingthe formula XI I{1X'-'-" wherein X, X, X and X are independentlyselected from O and S and R and R are independently selected fromhydrocarbon alkyl and aryl groups having from I to about 30 carbon atomsc. hydrocarbon carboxylic acids having from five to about 24 carbonatoms, and

d. naphthenicacids. Fuel compositions which are used in the preferredmethod contain 0.025 to about 6.45 grams of manganese per gallon as acyclopentadienyl manganese tricarbonyl and sufficient organic molybdenumcompound so that the atomic ratio of manganese (Mn): molybdenum (M0) isfrom about 5:1 to about 1:2. A ratio of MnzMo of about 1:1 to 4:1 ispreferred. Molybdenum dialkylphosphorodithioates or molybdenumnaphthenate and (methylcyclopentadienyl)manganese tricarbonyl in thepreferred ratio in the fuel are most preferred embodiments.

Manganese compounds which are useful as smoke reducers in jet fuels arecyclopentadienyl manganese tricarbonyls having the formula RMn(CO),wherein R is a cyclopentadienyl hydrocarbon radical having from five to17 carbon atoms. U. S. Pat. No. 2,8l8,4l7, issued Dec. 31, 1957,contains an extensive disclosure of the type of manganese compoundswhich are useful. This listing of compounds is incorporated byreference.

(Methylcyclopentadienyl)manganese tricarbonyl is an especially effectivesmoke reducer.

The concentration of the manganese tricarbonyl in the jet fuels may bevaried. Concentrations from 0.025 to about 6.45 grams of manganese pergallon as a cyclopentadienyl manganese tricarbonyl are useful.

By jet fuels, we include distillate hydrocarbons and blends which areuseful as fuel for jet engines. These fuels are principally hydrocarbondistillates heavier than gasoline. In other words, they are distillatehydrocarbon fuels having a higher end point than gasoline. They aregenerally composed of distillate fuels and naphthas and blends of theabove, including blends with lighter hydrocarbon fractions. The endpoint of preferable jet fuels is at least 435F..and more preferablygreater than 470F.

Typical jet fuels include JP-3, a mixture of about 70 per cent gasolineand 30 per cent light distillate having a 90 per cent evaporation pointof 470F.; JP-4, a mixture of about 65 per cent gasoline and 35 per centlight distillate especially designed for high altitude performance;JP-S, an especially fractionated kerosene and the like.

Molybdenum compounds which are useful in the present invention areorganic, oil soluble or oil dispersible compounds. They includemolybdenum salts, chelates, complex compounds and the like. Organicmolybdenum compounds which are oil soluble are preferred;by oil solubleis meant sufficient solubility in jet fuel to effect deposit reductionas herein described.

One class of useful organic molybdenum compounds are molybdenumchelates. These chelates are coordination compounds in which a centralmolybdenum atom is joined to two or more atoms of one or more othermolecules or ions (called ligands) so that one or more heterocyclicrings are formed with the central molybdenum atom as part of each ring.Examples of these compounds are chelate complexes of molybdenum withacetylacetone, N-nitrosophenylhydroxylamine, dimethylglyoxime,ethylenediamine, ethylenediaminetetraacetic acid, nitrilotriacetic acid,8-hydroxyquinoline, benzoylacetone and similar chelating agents.

Another class of useful organic compounds are the molybdenum phenates.These are salts of molybdenum and phenol or substituted phenols, andespecially C alkylphenols. The simplest member of this class ofcompounds is molybdenum phenate; representative formula for molybdenumphenates are Mo(OPh and wherein x is an integer from 2-6 inclusive andPh is the phenyl or substituted phenyl group. Salts of molybdenum andthe following phenols are useful 4-methylphenol 4-octadecylphenol4-oleylphenol 4-(2-ethyl-n-hexyl)phenol 2,6-dimethylphenol2,4,6-trimethylphenol o-chlorophenol 2-dodecylphenol 2,4-dododecylphenol4-nonylphenol Z-tert-butylphenol 3-nitrophenol and the like.

An especially useful type of a molybdenum phenate is that derived from acommercial mixture of alkylated phenols. Commercial alkylation ofphenols generally is accomplished by treating the phenol with an olefinor a mixture of olefins in the presence of an alkylating agent. Thiscommercial alkylation ordinarily produces a mixture of various alkylphenols. For example, if a phenol is alkylated with a C olefin, theproduct will contain monononylphenols, dinonylphenol, andtrinonylphenol. Likewise, if a mixture of C C C olefins is used in thealkylation, a mixture of various C C and C alkylated phenols isobtained. Molybdenum salts of these commercial mixtures of alkylatedphenols wherein the alkyl groups have from four to about 18 carbon atomsare also useful in the present invention.

Another class of useful compounds are molybdenum salts of hydrocarbonsubstituted phosphoric acids; these include the thiophosphoric acids.These phosphoric acids are represented by the following formula whereinX, X, X and X can be 0 and/or S and R and R are hydrocarbyl groups.Hydrocarbyl groups are hydrocarbon alkyl and aryl groups; hydrocarbylgroups having from one to about 30 carbon atoms are useful. Examples ofmolybdenum salts of acids of formula I areS-molybdenum-0,0-dimethylphosphorothioateO-molybdenum-O,O"-dioctylphosphorothioate molybdenum diphenylphosphatemolybdenum diciesylphosphate S-molybdenum-O,S'-didecylphosphorodithioatemolybdenum diamylphosphorotetrathioateO-molybdenum-S,S'-di-tert-butylphosphorotrithioateO-molybdenum-O,O"-dixylylphosphorothioateS-molybdenum-S',S"-di-4-ethylphenylphosphorotrithioate molybdenumdiactadecylphosphorotetrathioate molybdenum cresylphenylphosphateO-molybdenum-O',O"-dinaphthylphosphorothioateS-molybdenum-O,O"-diisopropylphosphorothioate molybdenumdibenzylphosphate and the like. Salts of dithiophosphoric acids wheretwo of X, X, X and X in Formula I are S are preferred. Examples ofpreferred salts are S-molybdenum-0,0'-dimethylphosphorodithioateS-molybdenum-0,0-dicresylphosphorodithioateS-molybdenum-QO'-di-4-dodecylphenylphosphorodithioateS-molybdenum-0,0'-dibenzylphosphorodithioateS-molybdenum-0,0'-dilaurylphosphorodithioateS-molybdenum-0,0'-di-2-ethylhexylphosphorodithioateS-molybdenum-0,0-diisobutylphosphorodithioateS-molybdenum-0,0'-methylphenylphosphorodithioateS-molybdenum-0,0'-dicyclohexylphosphorodithioateS-molybdenum-O,S-diamylphosphorodithioateS-molybdenum-O,S-diindenylphosphorodithioateS-molybdenum-QS-dixylylphosphorodithioateS-molybdenum-O,S-dioctadecylphosphorodithioateS-molybdenum-O,S'-diundecylphosphorodithioateO-molybdenum-S,S'-diheptylphosphorodithioateO-molybdenum-S,S'-di-2,6-tert-butylphenylphosphorodithioateO-molybdenum-S,S'-diethylphosphorodithioateO-molybdenum-S,S-ditetradecylphosphorodithioateO-molybdenum-O',S-diacetylphosphorodithioateO-molybdenum-O,S-di-2,4-didodecylphenylphosphorodithioateO-molybdenum-O,S-dioctadecylphosphorodithioateO-molybdenum-O',S-dihexylphosphorodithioate and the like.

Still another class of useful compounds are the salts of hydrocarboncarboxylic acids having from five to about 24 carbon atoms. Examples ofsuitable salts of this type are molybdenum pentanoate, molybdenumoleate, molybdenum linoleate, molybdenum adipate,molybdenum-2-ethylhexanoate, molybdenum benzoate, molybdenumtetradecanoate, molybdenum orthophthalate, molybdenum 4-dodecylbenzoate,molybdenum stearate, molybdenum laurate, molybdenum eicosanoate,molybdenum 4-methylpentanoate, molybdenum 4-methylbenzoate, molybdenumisovalerate, molybdenum B-napthoate, molybdenum phenylacetate,molybdenum 'y-phenylbutyrate, molybdenum o-toluate, molybdenumundecanoate, molybdenum trimethylacetate, molybdenum sebacate,molybdenum azelate, molybdenum 2,4,4-trimethylpentanoate, molybdenum2,4,4,6,6-pentamethylheptanoate and the like.

Molybdenum salts of mixtures of fatty acids obtained from naturalproducts such as olive oil, babassu oil, tall oil, cottonseed oil,tallow and the like are also useful. More preferred molybdenum compoundsof this type are the salts of alicyclic carboxylic acids. Specificexamples of useful molybdenum salts of alicyclic carboxylic acids aremolybdenum cyclopentane carboxylic acid, molybdenum cyclopentylacetate,molybdenum-3- methylcyclopentylacetate, molybdenum camphonanate,molybdenum cyclohexane carboxylate, molybdenum4-methylcyclohexanecarboxylate,

molybdenum-2,2,6-trimethylcyclohexane carboxylate and the like.

An especially preferred class of organic molybdenum salts are salts ofthe so-called naphthenic acids. The term naphthenic acids" is applied toa mixture of carboxylic acids obtained from the alkali washes ofpetroleum. These acids are complex mixtures of normal branched aliphaticacids, alkyl derivatives of cyclopentane and cyclohexane carboxylicacids and cyclopentyl and cyclohexyl derivatives of aliphatic acids. Thealicyclic carboxylic acids appear to be the major constituents of thesemixtures. The composition of these naphthenic acids will vary dependingon factors such as the source of petroleum, the refining procedure, etc.A more detailed discussion of these naphthenic acids is presented inChemical Technology of Petroleum," William A. Gruse and Donald R.Stevens 3rd edition, pages 6567, 1960, McGraw Hill Publishing Company;and is incorporated by reference.

For commercial use, the crude naphthenic acid mixture obtained in thealkali extract is generally refined to remove unsaponifiable material.Molybdenum salts of either the crude naphthenic acid mixture or of therefined naphthenic acid mixture are useful in the present invention. Themolybdenum salts of the refined naphthenic acids are especiallypreferred; the term molybdenum naphthenate will be used herein todescribe these especially preferred salts.

The amount of organic molybdenum compounds "described above which isadded to the organomanganese containing fuel may be varied. In general,sufficient organic molybdenum compound is added to the fuel so that theatomic ratio of molybdenum (Mo):

manganese (Mn) in the fuel is about 1:5 to about 2:1. It

EXAMPLE 1 To a .lP-S (ASTM-Type A) base fuel was added 2.58 grams/gallonof Mn as (methylcyclopentadienyl)manganese tricarbonyl and 59.84grams/gallon of a molybdenum dialkylphosphorodithioate.

The MnzMo atomic ratio of this composition is 1:1.

EXAMPLE 2 To a JP-S case fuel were added 2.5 8 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 29.92 grams/gallon ofa molybdenum dialkylphosphorodithioate.

The MnzMo atomic ratio of this composition is 2: 1.

EXAMPLE 3 To a .lP-S base fuel were added 2.58 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 14.96 grams/gallon ofa molybdenum dialkylphosphorodithioate.

The MnzMo atomic ratio of this composition is 4: 1.

EXAMPLE 4 To a JP-S base fuel were added 2.58 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 90.12 grams/gallon ofa molybdenum naphthenate.

The MnzMo atomic ratio of this composition is 1:1.

EXAMPLE 5 To a JP-S base fuel were added 2.58 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 45.06 grams/gallon ofa molybdenum naphthenate.

The MnzMo atomic ratio of this composition is 2: 1.

EXAMPLE 6 To a .lP-S base fuel were added 2.58 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 30.04 grams/gallon ofmolybdenum naphthenate.

The MnzMo atomic ratio of this composition is 3:1.

EXAMPLE 7 To a JP-5 base fuel are added 1.29 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 90.12 grams/gallon ofa molybdenum naphthenate.

The Mn:Mo atomic ratio of this composition is 1:2.

EXAMPLE 8 To a JP-S fuel are added 5.19 grams/gallon of Mn as(methylcyclopentadienyl)manganese tricarbonyl and 36.05 grams/gallon ofa molybdenum naphthenate.

The MnzMo atomic ratio of this composition is 5:1.

Useful jet fuel compositions having the deposit modifyingcharacteristics described below are also prepared (a) by using JP-4,JP-3 and the like in place of JP-S in the above examples, (b) by usingequivalent amounts of compounds such as molybdenum valerate, molybdenumchelate of B-hydroxy-quinoline, molybdenum chelate of phenylhydrazine,molybdenum chelate of acetylacetone, molydenum 2-methylphenate,molybdenum 2-methylphenate, molybdenum 4- dodecylphenate, molybdenumoleate, molybdenum 2- ethylhexanoate, molybdenum 4-isopropylbenzoate,molybdenum cyclohexanecarboxylate, S-molybdenum- S ,S-didecylphosphorotetrathioate, S-molybdenum-O,S'-dibutylphosphorotrithioate, o-molybdenum-0',O"-diphenylphosphorothioate and the like in place of the molybdenumcompounds in the above examples.

These jet fuel compositions are prepared by simply blending the requiredamount of manganese-containing smoke reducer and molybdenum depositreducing compound with the base jet fuel. Conventional fuel blendingapparatus and techniques are used.

When a jet fuel containing an organomanganese compound as a smokereducer is burned in a jet engine, a manganese containing deposit isformed on parts of the engine which come in contact with the burningfuel and/or its combustion products. Quite unexpectedly, by adding asmall mount of organic molybdenum compound to the fuel before burning,the amount of deposit is significantly reduced.

This unexpected deposit reducing effect was demonstrated by using thefollowing laboratory procedure. This test procedure was designed tosimulate jet engine conditions.

A clean metal test specimen was placed in the exhaust opening of atubular burner fueled with the control fuel, JP-S containing 2.58grams/gallon of manganese as (methylcyclopentadienyl)manganesetricarbonyl. The burner was ignited and the test specimen was exposed tothe exhaust stream until a certain amount of fuel was burned. The testspecimen was then removed from the exhaust stream and weighed. The totalweight of deposit formed was determined by subtracting the weight of theclean test piece from the test piece after exposure to the exhauststream.

A second clean test specimen was placed in the exhaust opening of thejet burner, now fueled with a JP-S fuel composition containing(methylcyclopentadienyl)manganese tricarbonyl and an organic molybdenumcompound. The jet burner was ignited and the test piece was exposed tothe exhaust stream until an amount of this fuel equivalent to thecontrol fuel was burned. The coated test piece was then removed from theexhaust stream and weighed. The amount of deposit was determined bysubtracting the clean test piece weight from the coated test pieceweight. Data for a series of such tests is presented in Table 1 below.

TABLE 1 Effect of Molybdenum on Deposit Amount of deposit Test FuelComposition deposit reduction 1 JP- Mn compound" 82 mg. 2 Example 4 53mg. 35% 3 Example 5 56 mg. 32% 4 Example 6 60 mg. 27%

(l) 2.58 grams/gallon of Mn as (methylcyclopentadienyl) manganesetricarbonyl.

The data in Table 1 clearly illustrates the deposit reducingeffectiveness of the organic molybdenum compounds. Comparable depositreduction is obtained using other molybdenum compounds as describedherein.

The method and fuels of the present invention are fully described above.It is intended that this invention be limited only within the spirit andlawful scope of the following claims.

CLAIMS 1. A method of reducing manganese containing deposits formed onthe surface of a jet engine from burning a fuel containing a smokereducing quantity of a cyclopentadienyl manganese tricarbonyl, whereinthe cyclopentadienyl radical has up to 17 carbon atoms; which comprisesadding to said fuel prior to burning, a deposit reducing amount oforganic molybdenum compound selected from the group consisting of l.molybdenum chelates and 2. molybdenum salts of a. phenol and C -C alkylsubstituted phenols b. phosphoric acids having the formula wherein X, X,X and X are independently selected from O and S and R and R areindependently selected from hydrocarbon alkyl and aryl groups havingfrom one to about 30 carbon atoms c. hydrocarbon carboxylic acids havingfrom five to about 24 carbon atoms, and

d. naphthenic acids, and burning the fuel in said engine.

2. The method of claim 1 wherein the amount of organic molybdenumcompound present is sufficient to give an atomic ratio of manganese tomolybdenum of from about 5:1 to about 1:2.

3. The method of claim 2 wherein said organic molybdenum compound ismolybdenum naphthenate.

4. The method of claim 2 wherein said organic molybdenum compound is amolybdenum dialkylphosphorodithioate.

5. The method of claim 2 wherein said cyclopentadienyl manganesetricarbonyl is (methylcyclopentadienyl)manganese tricarbonyl.

6. The method of claim 5 wherein said organic manganese compound is amolybdenum salt of said phosphoric acid.

7. The method of claim 6 wherein two of X, X, X and X of said phosphoricacid are S and wherein said atomic ratio is 4:1 to about 1:1.

8. The method of claim 5 wherein said molybdenum compound is molybdenumnaphthenate and said atomic ratio is from about 3:1 to about 1:1.

9. Jet fuel containing a smoke reducing quantity of a cyclopentadienylmanganese tricarbonyl, wherein the cyclopentadienyl radical has up to 17carbon atoms and manganese containing deposit reducing amount of organicmolybdenum compound selected from the group consisting of l. molybdenumchelates and 2. molybdenum salts of a. phenol and C alkyl substitutedphenols b. phosphoric acids having the formula wherein X, X X and X areindependently selected from O and S and R and R are independentlyselected from hydrocarbon alkyl and aryl groups having from 1 to about30 carbon atoms 0. hydrocarbon carboxylic acids having from S to about24 carbon atoms, and d. naphthenic acids, wherein the amount of saidmanganese compound and said molybdenum compound is sufficient to give anatomic ratio of manganese to molybdenum of from about 5:1 to about 1:2.

10. The jet fuel of claim 9 wherein said molybdenum compound ismolybdenum naphthenate.

11. The jet fuel of claim 9 wherein said molybdenum compound is amolybdenum dialkylphosphorodithioate.

12. The jet fuel of claim 9 wherein said manganese compound is(methylcyclopentadienyl)manganese tricarbonyl.

mg Wrap mm raramr omen QEEIIW 'CAM Cl @Chfittfldfi Patent No. 5s 7 ADatad February 27, 975

' m Vincent F, Hnizda I: la certified that error appaara in theabove-identified patent and that @aid Letters Patent are herebycorrected as shown below:

In Column 1, lines 54-56 that portion of the formula a? reading:

H P P II should read H In Column 5; line 57 case should read base InColumn 7, lines 65-67 (Claim 1) that portion of the formula reading:

P I P Y r X3 .X II'" should read H In Column 8, lines 45-47 (Claim 9)that portion of the formula reading:

X 3 II should read H Signed and sealed this 10th day of July 1973.

(SEAL) Attest: n

EDWARD M.F.LETCHER,JR. ene Tegtmeyer Attesting Officer Acting COmmiSS IPatents

2. The method of claim 1 wherein the amount of organic molybdenumcompound present is sufficient to give an atomic ratio of manganese tomolybdenum of from about 5:1 to about 1:
 2. 2. molybdenum salts of a.phenol and C1-C12 alkyl substituted phenols b. phosphoric acids havingthe formula
 2. molybdenum salts of a. phenol and C1-C12 alkylsubstituted phenols b. phosphoric acids having the formula
 3. The methodof claim 2 wherein said organic molybdenum compound is molybdenumnaphthenate.
 4. The method of claim 2 wherein said organic molybdenumcompound is a molybdenum dialkylphosphorodithioate.
 5. The method ofclaim 2 wherein said cyclopentadienyl manganese tricarbonyl is(methylcyclopentadienyl)manganese tricarbonyl.
 6. The method of claim 5wherein said organic manganese compound is a molybdenum salt of saidphosphoric acid.
 7. The method of claim 6 wherein two of X, X1, X2 andX3 of said phosphoric acid are S and wherein said atomic ratio is 4:1 toabout 1:1.
 8. The method of claim 5 wherein said molybdenum compound ismolybdenum naphthenate and said atomic ratio is from about 3:1 to about1:1.
 9. Jet fuel containing a smoke reducing quantity of acyclopentadienyl manganese tricarbonyl, wherein the cyclopentadienylradical has up to 17 carbon atoms and manganese containing depositreducing amount of organic molybdenum compound selected from the groupconsisting of
 10. The jet fuel of claim 9 wherein said molybdenumcompound is molybdenum naphthenate.
 11. The jet fuel of claim 9 whereinsaid molybdenum compound is a molybdenum dialkylphosphorodithioate. 12.The jet fuel of claim 9 wherein said manganese compound is(methylcyclopentadienyl)manganese tricarbonyl.
 13. The jet fuel of claim12 wherein said molybdenum compound is a molybdenum salt of saidphosphoric acid wherein two of X, X1 , X2 and X3 are S and said atomicratio is 4:1 to about 1:1.
 14. The jet fuel of claim 9 wherein saidmolybdenum compound is molybdenum naphthenate and said atomic ratio isfrom about 3:1 to about 1:1.